1. Field of the Invention
The present invention relates generally to bus systems of a computer, and more specifically to input/output bus drivers for preventing collision of data accessing a common bus.
2. Description of the Related Art
In a computer system, a plurality of input/output bus drivers are used to access a bus. Each bus driver includes an input buffer for amplifying signals from the bus and a tristate output buffer for amplifying signals to the bus. The tristate output buffer has an enable/disable input terminal which is responsive to an enable pulse for enabling the output buffer to pass signals to the bus. In a sequential circuit, the arrival of a signal at two or more places may be significantly different, when it should have arrived at nearly the same time. Since an enable pulse for each tristate output buffer is propagated through a different path, skew is said to be present when the difference in arrival times is great enough to cause a bus collision if the bus is accessed successively. As the number of peripheral devices increases, the number of input/output bus drivers increases accordingly, and the probability of bus collisions increases.